作者:Masayuki Sato、Tsunehisa Oda、Ken-ichi Iwamoto、Emi Murakami
DOI:10.1016/s0040-4020(03)00326-0
日期:2003.4
Highly efficient methods for synthesizing metacyclophanes such as 2,6-bridged pyrones and pyridines are described. 4-Hydroxy-2-pyrone derivative 3 bridged at the 3 and 6-positions is readily available. This compound was transformed into 2,6-bridged 4-pyrone 4 on heating in ethanol or in hydrochloric acid. Heating 4 with ammonia or methylamine afforded the corresponding 2,6-bridged 4-pyrone 7 or 8.
描述了用于合成间环烷,例如2,6-桥联的吡啶和吡啶的高效方法。在3位和6位桥接的4-羟基-2-吡喃酮衍生物3是容易获得的。在乙醇或盐酸中加热,将该化合物转化为2,6-桥联的4-吡喃酮4。与氨或甲胺加热4得到相应的2,6-桥连的4-吡喃酮7或8。这些吡啶酮是通过用氨或甲胺处理直接由3合成的。这些方法对间环烷的桥长具有广泛的适用性。具有短桥(n = 8)和长桥(n= 18)以令人满意的产率合成。